The present invention relates generally to polymers with an absolute molecular weight, particularly ionene-type polymers. The present invention also relates to methods for the use of such absolute molecular weight polymers, especially as identification standards to determine the molecular weight of ionene polymers and as antimicrobial agents.
The term "polymer" is generally defined as:
A substance composed of very large molecules consisting essentially of recurring long chain structural units that distinguish polymers from other types of organic molecules . . . PA1 W and Y are chosen to be the same or different, and are selected from OH, NR.sup.1 R.sup.2, or N.sup.+ R.sup.1 R.sup.2 R.sup.3 (Z.sup.31 ); PA1 R.sup.1-3 may be the same or different and are selected from: CH.sub.3 and C.sub.2 -C.sub.24 primary, secondary or tertiary alkyl or cycloalkyl groups; C.sub.3 -C.sub.24 unsaturated hydrocarbon groups, including straight and branched chain alkenes; unsubstituted and variously substituted benzyl groups, particularly alkylated benzyl groups, where the alkyl group is as defined above; PA1 BT is any pair of methylene units linked by a connector, such as the 1,2-, 1,3- and 1,4-phenylenes, and is preferably the trans-1,4-but-2-enylidene spacer; PA1 A is R.sup.1 R.sup.2 N.sup.+ Z.sup.- ; PA1 Z.sup.- is the anion corresponding to a variety of pharmaceutically acceptable Br.o slashed.nsted acids; e.g., Br.sup.-, I.sup.-, Cl.sup.-, H.sub.2 PO.sub.4.sup.-, MeCO.sub.2.sup.- and Me.sub.3 CCO.sub.2.sup.- ; and PA1 n is an integer between 15 and 31. PA1 X.sup.- is a pharmaceutically acceptable anion, preferably a halide, particularly chloride; and PA1 n is an integer between 15 and 31.
Grant et al., Grant & Hackh's Chemical Dictionary, Fifth Edition, McGraw-Hill, New York:1987, page 462 (emphasis added). In addition, polymers (especially high molecular weight polymers) often exhibit characteristic properties, such as high viscosity, long-range elasticity and high strength.
Although there are a wide variety of polymer structures, polymers may be generally expressed as combinations of a limited number of different structural units. In many instances, a single type of structural unit is present. These structural units may be connected in any of a number of ways to form different types of polymers, which may be referred to as either linear or non-linear (branched). In linear polymers, the structural units are connected to one another in a linear sequence, such as depicted below: EQU A'-A-A-A-A-A-A-A-A-A" or A'-(A-).sub.x-2 A"
where the termini, A' and A", may or may not be identical, but neither may be identical to A, the repeating structural unit, and x represents the degree of polymerization. On the other hand, in non-linear, or branched, polymers, the structural units are connected in non-linear or branched fashion, such as depicted below: ##STR1## In fact, such branched structures may interconnect further to yield network structures, analogous to the spatial structures of graphite (planar network) or diamond (space network).
The degree of polymerization, represented by x, is an expression of the number of structural units in a given polymer molecule; however, this x becomes ambiguous when applied to an actual sample of polymeric material, since all of the polymer molecules in a given sample will not have the same value of x. In fact, the degree of polymerization in a given sample of polymeric material will vary over a considerable range, and the term "average degree of polymerization" is often used instead. The average degree of polymerization is obtained by dividing the total number of structural units by the total number of molecules. In similar manner, the molecular weight of a sample of polymeric material is also ambiguous; therefore, the terms "number average molecular weight"(M.sub.n) and "weight average molecular weight" (M.sub.w) are generally used. The number average molecular weight of a sample of polymeric material represents the mass of the sample divided by the number of moles it contains. In contrast, the weight average molecular weight can be represented by the equation: EQU M.sub.w =.SIGMA.W.sub.x M.sub.x
wherein w.sub.x is the weight-fraction of molecules whose weight is M.sub.x.
A general discussion of polymers may be found in a treatise by P. J. Flory (Principles of Polymer Chemistry, Cornell University Press, Ithaca: 1953) especially Chapter II, pages 29-68, and Chapter VIII, pages 317-346.
Average molecular weight estimations of these types of polymeric ionene materials have been performed by gel permeation chromatography, vapor pressure osmometry, etc., but none of these methods are reliable in estimating the molecular weight, and the determinations are dependent on other variables, such as the particular internal standards used and the purity of the polymeric material. Thus, the absolute molecular weight compounds of this invention should shed light on the characterizations of ionene-type polymeric materials, especially with regard to the estimation of molecular weight.
For purposes of this specification, the polymerization reactions, such as are described above, which produce polymers of varying sizes will be generically referred to as "conventional polymerization processes."